Gelation acceleration

Abstract

The invention provides a method made of steps of injecting into a wellbore, a composition comprising a solvent, a crosslinkable polymer, a crosslinking agent capable of crosslinking the polymer or forming a polymer, and a gelling accelerator selected from the group consisting of carbon dioxide, polylactic acid, encapsulated acid and latent acid; and allowing viscosity of the composition to increase and form a gel more quickly with the gelling accelerator than without.

1 . A method comprising:
 a. injecting into a wellbore, a composition comprising a solvent, a crosslinkable polymer, a crosslinking agent capable of crosslinking the polymer or forming a polymer, and a gelling accelerator selected from the group consisting of carbon dioxide, polylactic acid, encapsulated acid and latent acid;   b. allowing viscosity of the composition to increase and form a gel more quickly with the gelling accelerator than without.   
     
     
         2 . The method of  claim 1 , wherein the composition further comprises a foaming agent and a surfactant. 
     
     
         3 . The method of  claim 2 , wherein the foaming agent is the gelling accelerator. 
     
     
         4 . The method of  claim 3 , wherein the gelling accelerator is carbon dioxide. 
     
     
         5 . The method of  claim 1 , wherein the encapsulated acid or latent acid is sodium metabisulfite. 
     
     
         6 . The method of  claim 1 , wherein the solvent is water or brine. 
     
     
         7 . The method of  claim 1 , wherein the crosslinkable polymer comprises acrylamide polymer and copolymer. 
     
     
         8 . A method of treating a subterranean formation at least partially made of carbonate rock comprising:
 a. injecting into a wellbore, a composition comprising a solvent, a crosslinkable polymer, a crosslinking agent capable of crosslinking the polymer or forming a polymer, and a gelling accelerator, wherein the gelling accelerator is substantially inert to the carbonate rock;   b. contacting the composition with the subterranean formation, wherein the temperature is below 150 degrees Celsius at this contact;   c. allowing viscosity of the composition to increase and form a gel more quickly with the gelling accelerator than without.   
     
     
         9 . The method of  claim 8 , wherein the composition further comprises a foaming agent and a surfactant. 
     
     
         10 . The method of  claim 9 , wherein the foaming agent is the gelling accelerator. 
     
     
         11 . The method of  claim 10 , wherein the gelling accelerator is carbon dioxide. 
     
     
         12 . The method of  claim 8 , wherein the gelling accelerator is carbon dioxide. 
     
     
         13 . The method of  claim 8 , wherein the gelling accelerator is polylactic acid fiber. 
     
     
         14 . The method of  claim 8 , wherein the gelling accelerator is a delayed acid release component. 
     
     
         15 . The method of  claim 14 , wherein the gelling accelerator is encapsulated acid or latent acid. 
     
     
         16 . The method of  claim 15 , wherein the encapsulated acid or latent acid is sodium metabisulfite. 
     
     
         17 . The method of  claim 8 , wherein the solvent is water or brine. 
     
     
         18 . The method of  claim 8 , wherein the crosslinkable polymer comprises acrylamide polymer and copolymer. 
     
     
         19 . The method of  claim 8 , wherein the temperature is below 130 degrees Celsius. 
     
     
         20 . The method of  claim 8 , wherein the temperature is below 110 degrees Celsius. 
     
     
         21 . The method of  claim 8 , wherein the temperature is below 95 degrees Celsius. 
     
     
         22 . A method of treating a subterranean formation made at least partially of carbonate rock comprising:
 a. injecting into a wellbore, a composition comprising a solvent, a crosslinkable polymer, a crosslinking agent capable of crosslinking the polymer or forming a polymer, a surfactant and carbon dioxide;   b. contacting the composition with the subterranean formation, wherein the temperature is below 130 degrees Celsius at this contact;   c. allowing viscosity of the composition to increase and form a gel more quickly with the carbon dioxide than without.   
     
     
         23 . The method of  claim 22 , wherein the solvent is water or brine. 
     
     
         24 . The method of  claim 22 , wherein the crosslinkable polymer comprises acrylamide polymer and copolymer. 
     
     
         25 . The method of  claim 22 , wherein the temperature is below 110 degrees Celsius.